Recently, attention has been focused on wireless power supply techniques of supplying power without a cable. The electromagnetic induction technique, which is one of the wireless power supply techniques, supplies power by generating an induced current between a coil of a power supply device and a coil of a power receiver. The magnetic resonance technique, which is another one of the wireless power supply techniques, supplies power by causing an electrical resonance phenomenon between a coil of a power supply device and a coil of a power receiver. The magnetic resonance technique can supply power over longer distances than that of the electromagnetic induction technique.
With the wireless power supply techniques, the power supply efficiency may decrease depending on the positional relationship between the coils. A method is proposed of suppressing a decrease in the power supply efficiency by enlarging a region where the power supply efficiency is high (hereinafter referred to as “power supply region”) by the use of a movable power-supply coil or the use of a plurality of power-supply coils. In Japanese Patent Laid-Open No. 2001-197674, a method is proposed of suppressing a decrease in the power supply efficiency by inhibiting vibration of a power receiver during power supply when the power receiver includes a vibrating unit, for example, when the power receiver is a cellular phone.
However, even while the power receiver receives power, inhibition of vibration of the power receiver may be unnecessary. For example, it is unnecessary when the power receiver is receiving power through a cable or when the power transmitting region of the power transmitter is large and vibration of the power receiver does not cause the power receiver to deviate from the power transmitting region.
If vibration of the power receiver is inhibited in such cases, a user is unable to notice, for example, an incoming call or a predetermined time by vibration, and user convenience decreases.
In light of the above problem, it is an object of the instant subject matter to selectively inhibit vibration of a power receiver during power reception, depending on the power reception status. In another aspect of the present invention, it is an object to notify a user of inhibition of vibration of the power receiver during power reception.